title: Spectroscopic characterization of charge transfer complexes of 2,3-diaminopyridine with chloranilic acid and dihydroxy-p-benzoquinone in polar solvent.
abstract: Charge transfer (CT) complexes formed between 2,3-aminopyridine (2,3-DAP) as electron donor with the π-electron acceptors chloranilic acid (CHA) and dihydroxy-p-benzoquinone (DHBQ) were investigated spectrophotometrically in ethanol. Minimum-maximum absorbance method has been used for estimating the formation constants of the charge transfer reactions (KCT). Job's method of continuous variation and photometric titration studies were used to detect the stoichiometric ratios of the formed complexes and they showed that 1:1 complexes were produced. The molar extinction coefficient (ε), oscillator strength (f), dipole moment (μ), charge transfer energy (ECT), ionization potential (IP) and the dissociation energy (W) of the formed complexes were estimated, they reached acceptable values suggesting the stability of the formed CT-complexes. The solid CT-complexes were synthesized and characterized by elemental analyses, (1)H NMR and FTIR spectroscopies where the formed complexes included proton and electron transfer.
authors.affiliation: Chemistry Department, Sciences Faculty for Girls, King Abdulaziz University, Jeddah, Saudi Arabia. Electronic address: khairiaalahmary@yahoo.com.
authors.forename: Khairia M
authors.initials: KM
authors.lastname: Al-Ahmary
mesh_terms: D000631:Aminopyridines / Q000737:chemistry*; D016227:Benzoquinones / Q000737:chemistry*; D004579:Electron Transport; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D012997:Solvents / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics
chemical_list: D000631:Aminopyridines; D016227:Benzoquinones; D012997:Solvents; C004532:quinone; C038615:2,3-diaminopyridine; C014400:chloranilic acid
keywords: (1)H NMR; 2,3-Aminopyridine; Chloranilic acid; Dihydroxy-p-benzoquinone; FTIR; UV–Vis